#define  _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
# include<queue>
using namespace std;

void test_queue1()
{
	queue<int> q;
	q.push(1);
	q.push(2);
	q.push(3);
	q.push(4);

	while (!q.empty())
	{
		cout << q.front() << " ";
		q.pop();
	}
	cout << endl;
}

int main()
{
	test_queue1();

	return 0;
}